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A. c. LUDLUM AND A. LOWY.

GOLD DRE DGE. APPLICATION FILED MAR- 20; 1916.

1,315,228. Patented Sept. 9,1919.

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A. c. LUDLUM ANDA. LOWY.

sou) DREDGE.

APPLICATION FILED MAR-20-19l6.

l 8 1 5,228 I Patented Sept. 9, 1919.

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A. C. LUDLUM AND A. LOWY.

ecu) DREDGE.

APPLICATION FILED MAR. 20. I916.

Patented Sept. 9,1919.

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A. C. LUDLUM AND A. LOWY.

GOLD DRE'DGE. APPLICATION FILE'D MAR. 20

1919. 4 SHEETS-SHEE T 4- Patented Sept. 9

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sirarns rnrnnr osmium ALBERT C. LUZDLUM, OIE NEW YORK, N. 'Y., AND LO'WY, 0F NEWARK, NEW JERSEY, ASSIGNORS TO NEW YORK ENGINEERING COMPANY, A CORPORATION -OF new YonK.

GOLD-DRElDGE.

Patented Sept. 9, 1919.

Application filed March 20, 1916. i Serial No. 85,281.

To all whom it may concern:

Be itknown that we, ALBERT C. LUDLUM and Ami-Ion LOWY, citizens of the United States, residing at New York, in the county of New York and State of New York, and Newark, in the county of Essex and State of New Jersey, respectively, have invented certain new and useful Improvements in Gold-Dredges, of which the following is a full, clear, and exact specification.

This invention relates to improvements in gold dredges and has especial reference to the provision of means for discharging clay and other analogous materials which may be taken up by the dredging buckets independently of the screen and the gold saving tables. i a i c t The object of this invention is to provide a system of controlling gates and claycon veyers leading therefrom whereby materials which it is not desired to pass through the screen or over the tables can be rapidly handied and discharged independently of both the screen and the gold saving tables. Not only can such materials be handled more quickly by means of this invention, but no time is lost when pay dirt is reached in changing the delivery so that none of the values will be lost. The dredge buckets discharge into a vertically disposedhop per, the lower end of which discharges into theinterior of the screen. Intermediately connected to the hopper is a gravity clay chute which is controlled by a vertically swinging gate which, when in vertical position, leaves the discharge to the screen clear, and when in a:

horizontal position obstructs the hopper and discharges the clay or other unworkable material into the gravity clay chute, which thence discharges into one or noreclay conveyers. Preferably, a plurality ofclay conveyers are provided leading from a single chute, and controlled by a'swi-nging gate or switch so as to permit of being used alternately in order to spread the discharged material over a wide area astern of the hull.

A further feature of the invention consists in combining withthe clay chute which leads to the clay sluices a water nozzle which is specially constructed to discharge a flat stream of water under pressure on the bottom of the chute so; thatmaterial falling thereon from the digger will be flushed downward and carried away without splashing over theadjaccnt parts of the machinery. Previous attempts to rapidly dispose of clay by means of water jets have been ob ect1onable and unsatisfactory, because the force of the water was such as to splash muddywater over other parts of the dredge, necessitating additional labor in order to enable the parts to properly operate.

By the present invention, large quantities of clay and similar objectionable materials can be handled without obstructing the screen and gold saving tables, and the discharges of clay, gangue and tailings can be more easily distributed astern of the dredge.

In the accompanying drawings,

Figures 1 and 2 are elevations of a dredge embodying the invention;

Fig. 3 is a plan view;

gig. 4: is a detail View on an enlarged scale, an

Fig. 5 is a plan view of part of Fig. 4.

1 1 represents a float or hull carrying a ladderframe 2 on which is an endless chain of buckets 3 running over a wheel 4: atthe bottom and a wheel 5 at the top, the wheel 5 being carried by shaft 6. The power is for nished by a steam boiler 7 whichfdperatcs a turbine 8 which is directly coupled to drive a generator 9. 10 is a condenser, 11 a winch for lifting the ladder driven by auxiliary motor 12, 13 is a high pressure pump driven by auxiliarymotor 14, the pump discharge being by pipe 15 to the condenser to pipe 17 and also by pipe18 toaperforated pipe 19 insidethe rotary screen 20. The screen 20 is shown in Fig. 4: and consists of an inclined cylindercarrying external bearings 21 riding-on rollers 22, and perforated so as to passthe line dirt and the values through to the gold tables 23 and sluices 24. The sluices 24 discharge into tail sluices 25 in the usual manner. The gangue or coarse tailings is discharged from the lower end of the screen 20 on to a stacker 27, which conveys it upwardly and discharges sufficiently far from the float toprevent interference.

The-material from the buckets 3 falls out by gravity as they pass around the wheel 5, and falls down through a hopper 28 on to the inclined bottom 29, and thence by to the tables if fine enough, andif not, passing out through the lower end on to the stacker 27. In order to enable the clay to be more quickly disposed of, the hopper 28 is provided with a horizontally pivoted vertically swinging gate 35 pivoted at 36 to the side of the hopper and operated through segment 37 and gear 38 from hand wheel 39. The gate 35 swings downward until stopped in an inclined position by abutments 40, at which position it forms an apron which discharges the material into the inclined trough conveyer '42, from which the material passes to branch trough conveyers 43, 43. The conveyer 42, the gate 35, the nozzle 47, the gate 44, and the branch trough conveyers 43, are all disposed above the upper side of screen 20,- so that the conveyers 42 and 43 of simple trough form enable large quantities of materials either wet or dry to be handled and discharged by gravity without requiring additional lifting power, or attention. The chain bucket digger may at times bring up water or mud, as well as comparatively dry solid material, and it is more economical and simple to dispose of all such materials by gravity flow directly overboard through the trough conveyers 43 rather than through the tail sluices from the tables, or by additional pumps or lifting conveyers below the screen and tables. 44 is a swinging gate or switch which in one position cuts off one branch conveyer and in the other position cuts elf the other, so that the clay can be distributed behind the dredge and 011 either side so as not to accumulate in one place and obstruct its movement. When the gate 35 is in vertical position it completes the vertical wall of the hopper above the screen and preventsescape of the value containing material. 7

The clay as discharged by the buckets 3 does not flow very easily, and in order to remove the clay quickly a novel arrangement of 7 water flushing is provided. Branching from the pipe 18 is a water pipe 46, which leads to a horizontal flat or elongated nozzle aperturej47 formed in a casting'48 extending across the bottom of the conveyer 42 immediately in front of the pivot 36 and gate 35. A series of horizontal jets similarly discharging could be used. This nozzle 47 discharges a flat sheet of water under pressure along the bottom of the conveyer 42, so that the clay slides or falls down the incline of gate 35 over the mouth of the nozzle and is flushed away down conveyer 43 by the force of the water.

Owing to the water being discharged along the bottom of the conveyer in the same direction as the clay there is little or no splashing, and the clay is prevented from adhering or clogging the conveyers. By this arrangement, it is possible to handle a vmuch largervolume of unworkable material way of illustration only, and various modifications and changes in the form and location may be made without departing from the scope of the appended claims.

Having thus described our invention, we

declare that what we claim as new and desire to secure by Letters Patent, is

1. The combination in a gold dredge with a digger discharging by gravity at the top of the lift, of a hopper below the top of the digger receiving the discharged material and having a fixed inclined bottom to discharge the material into an inclined screen, an inclined screen directly receiving the material discharged from the bottom of the hopper, saving tables below the screen, a down eonveyer above and generally parallel to the bottom of the screen and discharging independently of the screen and the tables, a discharge opening through the side of the hop per to said down conveyer, and a gate piv oted on the side of said hopper below said opening and above said fixed bottom discharge and movable inwardly from a vertical position closing access of material to said down conveyer to an inclined position across the hopper to discharge material directly from the digger to said conveyer and cutting off material from the hopper bottom discharge into said screen.

2. The combination in a gold dredge with a chain bucket digger discharging by gravity at the top of the lift, of a hopper below the top of the digger receiving the discharged material and having a fixed inclined bottom to discharge the material into an inclined rotary screen, an inclined rotary screen directly receiving the material discharged from the bottom of the hopper, saving tables below the screen, a down trough conveyer above and generally parallel to the bottom of the screen and discharging independently of the screen and the tables, a discharge opening through the side of the hopper to said down conveyer, means for discharging water under pressure down the bottom of said trough conveyer for preventing adherence of clayey material thereto and accelerating the flow, and a gate pivoted on the side of said hopper below said opening and above said fixed bottom discharge and movable inwardly from a vertical position closing access of material to said down conveyer to an inclined position across the hopper to discharge material directly from the digger to said conveyer and cutting oif material from the hopper bottom discharge into said screen.

3. In a gold dredge embodying a digger for lifting the material and a screen and saving tables below the top of the digger lift fed thereby by gravity, a down trough conveyer between the screeen and the digger controlled by a movable gate diverting Waste material thereto before it falls into the screen, and a flat downwardly directed Water nozzle adjacent the upper end of the trough conveyer for discharging a fiat sheet of water under pressure down along the bottom of the conveyel' for preventing ad- 10 herence of clayey material thereto and accelerating the flow.

In testimony whereof we aflix our signatures.

ALBERT C. LUDLUM. ARTHUR LOWY.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

